Obejective To conduct fast identification analysis on chemical constituents of Mori Folium UPLC-Q-TOF/MS method. Methods ACQUITY UPLC-Q-TOF/MS spectrometer was used, acetonitrile and water （containing 0.1% formic acid） as mobile phase with gradient elution. The flow rate was 0.3 mL/min, with ESI negative ion mode detection, data analysis with Masslynx4.1 software. Results According to the retention time provided by the mass spectrometry, the exact molecular weight and the secondary mass spectrometry were used to analyze the fragments by referring to literature, and 19 chemical constituents of Mori Folium were identified and deduced. Conclusion The method can analyze the chemical constituents of Mori Folium rapidly, sensitively and comprehensively, and provide the basis for the study of the pharmacological basis of Mori Folium.